|
Basic Characteristics of Mutations
|
|
Mutation Site
|
K209N |
|
Mutation Site Sentence
|
B/Victoria-lineage viruses with the three-amino-acid deletion fell into two distinct subgroups (Figure 1B): one subgroup shared an amino acid substitution at position K136E, and the other subgroup had two common amino acid substitutions at I180T and K209N. |
|
Mutation Level
|
Amino acid level |
|
Mutation Type
|
Nonsynonymous substitution |
|
Gene/Protein/Region
|
HA |
|
Standardized Encoding Gene
|
HA
|
|
Genotype/Subtype
|
B/Yamagata;B/Victoria |
|
Viral Reference
|
B/Victoria
|
|
Functional Impact and Mechanisms
|
|
Disease
|
Influenza B
|
|
Immune
|
- |
|
Target Gene
|
-
|
|
Clinical and Epidemiological Correlations
|
|
Clinical Information
|
- |
|
Treatment
|
- |
|
Location
|
Japan |
|
Literature Information
|
|
PMID
|
31955521
|
|
Title
|
Antigenic variants of influenza B viruses isolated in Japan during the 2017-2018 and 2018-2019 influenza seasons
|
|
Author
|
Kato-Miyashita S,Sakai-Tagawa Y,Yamashita M,Iwatsuki-Horimoto K,Ito M,Tokita A,Hagiwara H,Izumida N,Nishino T,Wada N,Koga M,Adachi E,Jubishi D,Yotsuyanagi H,Kawaoka Y,Imai M
|
|
Journal
|
Influenza and other respiratory viruses
|
|
Journal Info
|
2020 May;14(3):311-319
|
|
Abstract
|
BACKGROUND: Here, we genetically and antigenically analyzed influenza B viruses (IBVs) isolated in Japan during the 2017-2018 and 2018-2019 influenza seasons. METHODS: A total of 68 IBVs (61 B/Yamagata/16/88-like [B/Yamagata]-lineage and 7 B/Victoria/2/87-like [B/Victoria]-lineage) were antigenically and genetically characterized by using hemagglutination inhibition (HI) assays and phylogenetic analysis, respectively. The susceptibility of IBVs to neuraminidase (NA) inhibitors was assessed by using a fluorescence-based NA inhibition assay. RESULTS: All 61 B/Yamagata-lineage isolates were genetically closely related to B/Phuket/3073/2013, the vaccine strain for these two seasons. Eleven B/Yamagata-lineage isolates tested were antigenically similar to B/Phuket/3073/2013 by the HI test. Seven B/Victoria-lineage isolates were genetically closely related to B/Texas/02/2013, the WHO-recommended vaccine strain for the 2017-2018 season; however, they were antigenically distinct from B/Texas/02/2013 with an eightfold or 16-fold difference in HI titer. Of these 7 isolates, 4 possessed a two-amino-acid deletion at positions 162 and 163 in hemagglutinin (HA) and the other 3 had a three-amino-acid deletion at positions 162-164 in HA. Importantly, the variants with the three-amino-acid deletion appeared to be antigenically different from the B/Colorado/06/2017 virus with the two-amino-acid deletion, the vaccine strain for the 2018-2019 season with a fourfold or eightfold difference in HI titer. One B/Yamagata-lineage isolate carrying a G407S mutation in its NA showed a marked reduction in susceptibility to zanamivir, peramivir, and laninamivir. CONCLUSIONS: These results highlight the need for continued monitoring for the prevalence of the antigenic variant with the three-amino-acid deletion and the variant with reduced NA inhibitor susceptibility.
|
|
Sequence Data
|
-
|
|
|